Microwave satellite communication links with data rate of about 500 Mb/s does not possess enough capacity to meet the increasing data transmission demand. Optical communication links with data rates of 40 Gb/s and above can be adapted for high speed satellite communication network, which in particular may include multi channel video data broadcast.
U.S. Pat. No. 6,782,212 and U.S. Pat. No. 6,798,994 by Tsao disclose an optical satellite communication with coherent detection, which is considered be the most promising configuration of the future optical satellite networks. In particular they address the problem of laser frequency drifting and the methods of its compensation. However those patents did not explore the signal corruption caused by the additive phase-noise resulting from vibration onboard the satellite.
Various approaches for additive noise cancellation in optical systems are disclosed in the U.S. Pat. No. 5,157,596 by Alcone et al., U.S. Pat. No. 6,034,760 by Ress, F., U.S. Pat. No. 6,393,311 by Edgar et al.; U.S. Patent application No. 20040071207 by Skidmore; and U.S. Patent application No. 20040155794 by Gardner, incorporated herein by references.
There is still a need to improve stability and accelerate convergence algorithm for data processing in communications systems, to recover reliable data in worse signal-to-noise (SNR) scenario, to provide system operation in the presence of wide spectrum additive noise. The system disclosed in the present invention addresses the drawbacks listed above of the prior art.
It is well known ionizing radiation, such as cosmic rays, gamma rays, and hard X-rays degrade electro-optical device performance in space. U.S. Pat. No. 6,605,818 discloses a protective coating composition and a method of its deposition to protect opto-electronics from harmful radiation. There is a need for a complex approach to the development of satellite communication system transceivers, which includes both vibration elimination and protection from ionizing radiation.